JPH0527025Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a watch case structure for positioning the watch case and the main plate in which movement parts are assembled in advance.

[Conventional technology]

A conventional positioning structure between a watch case and a main plate incorporating movement parts was as shown in FIGS. 4 and 5. That is, in FIGS. 4 and 5, 11 is a watch case, 13 is a movement,
15 is a dial, 16 is a needle, and 17 is a glass.
The upward positioning of the movement 13 is performed by a glass 17 that is ultrasonically welded to the case 11 via the dial 15. Further, horizontal positioning is performed by a movement drop diameter 13a of the movement 13 and a movement guide protrusion 11c of the case 11. Also, attempts have been made to use pins 12a to position the case 11 and the pallet 12 for automatic assembly and transportation.

[Problem that the invention attempts to solve]

However, in the prior art described above, all or part of the movement drop diameter 13a is used as a positioning surface, and the positioning accuracy of the movement 13 with respect to the watch case 11 is about 0.1 mm.
Therefore, it has been common practice to set the dial 15 and hands 16 in the movement 13 in advance, and then manually set the movement 13 into the case 11. For this reason, there are problems in terms of cost, such as that it is difficult to fully automate the movement, and that a leg 15a for positioning the dial plate with respect to the movement is required.

The present invention is intended to solve these problems, and its purpose is to provide a cost-competitive watch case.

[Means for solving problems]

The watch case structure of the present invention includes a movement in which a through hole is formed, and a case made of synthetic resin in which the bottom of the case back cover and the body of the case are integrated.
The case has a protrusion formed protruding from the bottom of the back cover and installed in the through hole to position and fix the movement in the horizontal and vertical directions, and a blind hole formed at a position that overlaps the protrusion in plan view. It is characterized by having.

〔Example〕

1 and 2 are cross-sectional views of essential parts showing an embodiment of the present invention, and FIG. 3 is a plan view showing the relationship between the movement and the case, in which 1 indicates the case back bottom 1a and the case body. The case consists of a 1m long case, 3 is a movement consisting of a main plate incorporating movement parts, 5 is a dial, 6 is a hand, 7 is a glass, and 8 is a battery cover. Inside the back cover bottom 1a of the case 1, two or more protrusions 1c (four in the embodiment) for fixing the movement are provided. By attaching a through hole 3a provided in the inner circumferential portion to the protrusion 1c at a position corresponding to the protrusion 1c of the main plate into which movement parts such as a crystal oscillator, gears, circuits, and coils are incorporated, the movement 3 relative to the case 1 is Perform horizontal positioning. Also, movement 3
and pallet 2 for automatic assembly and transportation used during automatic assembly.
Horizontal positioning with pin 2 of pallet 2
a and the blind hole 1b of case 1. Note that the blind hole 1b may be a through hole. The case back bottom 1a and the main plate positioning protrusion 1c are located on the case body.
It is made of the same plastic material as 1m and is integrally injection molded. Protrusion 1c for positioning the main plate
After the movement 3 is attached to the case 1, the tip part 1e of the movement 3 is ultrasonic staking (ultrasonic caulking) or heat caulked to form the flange part 1k of the protrusion 1c. (vertical direction) positioning. The material of case 1 is made of plastic material such as ABS polycarbonate. Assembly is done using pallets 2 for automatic assembly and transportation.
Place the case 1 so that the blind hole 1b is aligned with the guide pin 2a of the case 1, and install the movement 3 so that the through hole 3a is aligned with the protrusion 1c of the case 1.
The flange part 1k is formed by ultrasonic caulking, the movement 3 is fixed to the case 1, and then the dial 5 is fixed to the case 1.
The footless dial 5, which is positioned by the notch 5a provided on the outer periphery of the case 1, is attached, and the hands 6, the crown 4 having the winding stem 4a, and the glass 7 are attached in this order. These assemblies are fully automated, and for this purpose, parts mounting parts for the protrusions 1c,
In other words, the positional accuracy of the dial entry diameter 1i, glass entry diameter 1j, ribbon entry diameter 1battery lid entry diameter 1h, blind hole 1b for guiding the pallet for automatic assembly conveyance, etc. is determined by simultaneous injection molding using the same material. Therefore, it can be sufficiently controlled to about 0.03mm. Furthermore, since the movement 3 is fixed to the case 1 at the flange 1k, the impact force of the movement 3 is not applied to the dial 5 due to a drop or the like. Therefore, the dial 5 does not require rigidity like metal, and can be made of paper, plastic film, thin film material, or the like.

In the past, a method of directly assembling movement parts into the case was considered, but in this case, there were restrictions on the material used for the exterior, the defective rate of the case and the movement was combined, resulting in a lower rate of good products, and there was a problem with the manufacturing process of the movement. Although there are many restrictions such as not being able to sell only the movement and the movement, the main plate with movement parts installed in advance can be used separately from the case, and the above disadvantages can be avoided.

Blind hole 1 for positioning provided on the opposite side of the protrusion 1c
b also has the effect of preventing sinking of the protrusion 1c that tends to occur on the bottom surface 1d of the back cover.

The tip end 1e of the protrusion 1c shows the shape of the protrusion 1c before caulking, and has a slope 1f that facilitates mounting of the movement. Further, vertical positioning of the movement 3 and the case 1 is performed by a stepped portion 1g of the projection 1e.

Vertical positioning of the movement 3 and the pallet 2 for automatic assembly and conveyance is performed on the plane 1d, and by controlling the height of the range A, it is possible to easily control the vertical dimension with high precision.

[Effect of idea]

As described above, according to the present invention, the protrusion formed at the bottom of the case back cover is attached to the through hole formed in the movement, and the movement is positioned and fixed in the horizontal and vertical directions.
Since high positional accuracy can be ensured with a simple configuration, automatic assembly of each watch component is extremely easy. In addition, the case has a blind hole formed at a position that overlaps the protrusion in a plane, so for example, during automatic assembly, the case can be easily mounted on a pallet for automatic assembly and transportation by using this blind hole. In addition to this, it also has the effect of preventing sink marks caused by differences in wall thickness of the protrusions during injection molding of the case.

[Brief explanation of the drawing]

1 and 2 are sectional views of essential parts showing an embodiment of the watch case structure of the present invention. Figure 3 is a plan view of the invention showing the relationship between the movement and the case. FIG. 4 is a cross-sectional view of the main parts of a conventional watch case structure.
FIG. 5 is a plan view of FIG. 4. 1...Case, 1c...Protrusion, 1k...Brim, 1b...Blind hole, 1a...Bottom of case back cover,
1m...Case body, 3...Movement, 3a
...Through hole, 5...Dial, 6...Hand, 7...Glass, 4...Ryuzu.

Claims (1)

[Scope of utility model registration request] It has a movement in which a through hole is formed, and a case made of synthetic resin, in which the bottom of the case back cover and the body of the case are integrated, and the case is formed to protrude from the bottom of the case back, and is attached to the through hole. A watch case structure characterized by having a protrusion for positioning and fixing a movement in the horizontal and vertical directions, and a blind hole formed at a position that overlaps the protrusion in plan view.